The present invention relates to an odor adsorbing agent which is intended to find an application in the area of hygiene articles, such as diapers, sanitary napkins, tampons and other incontinence articles. The odor adsorption agent is intended to have the capability of combating a broad spectrum of unpleasant smelling odors.
Hygiene articles are very often designed not only with the purpose in mind that they should have the best possible absorption capability for body fluids, such as blood, menses and urine, but beyond that with respect to their hygienic characteristics and their comfort in use. Disposable products such as diapers and panty liners normally consist of a fluid-permeable topsheet, an absorbent core and a fluid-impermeable backsheet. Hygiene articles exist in the widest variety of sizes, shapes and thicknesses.
One particular aspect of this type of hygiene article is the control of resulting odors. Many body fluids have the unpleasant characteristic of emitting an odor, or, in conjunction with air or bacteria, of generating a similar odor for a prolonged period.
From the prior art, a wide variety of materials is known as an odor adsorbent. Zeolites in particular are used for this purpose. Zeolites are normally used in the form of small particles, so that the zeolite material is present in powder form. A zeolite powder of this kind has the disadvantage that it is difficult to handle in industrial settings. Zeolite powders tends to create dust and additionally have the characteristic of detaching, or separating out, from the absorbent structure of the hygiene article in which they are contained. This is particularly the case with the high processing speeds which are prevalent on modem machines producing diapers, for example.
Thus it is known from the prior art to combine zeolites with amorphous silicic acid into agglomerates.
Furthermore it is disclosed in the prior art, for example in EP 0 515 477 B1, to bond zeolites to the absorption means, such as a superabsorbent polymer, by means of chemical bonds. However, as a result of this bond the SAP characteristics, and thus the absorption characteristics for body fluids are changed. The bond takes place in the form of a cohesive mixture with the addition of a binder, specifically hydroxypropyl cellulose.
A further disadvantage of the binding of zeolite to SAP is that the zeolite can only be added in metered quantities together with the SAP, but the anchoring of the zeolite to the SAP is weak. If the bond between zeolite and SAP is broken, the known dust problems re-occur. It is further known, for example, from PCT/US/99/02760 to bond zeolites into a polymer matrix, where the matrix has a polymer of functional groups which react with the zeolite and as a result bind it to themselves.
Finally, it is known from DE-OS 21 64 262 to bond adsorbents to “bi-component fibers”. These fibers are, for one, expensive in production and, secondly, difficult to incorporate into the absorbent structure of a hygiene article.
The object of the invention is to prepare an odor adsorption agent and a hygiene article and a method for producing an odor adsorption agent which is simple to handle on an industrial scale, has good odor adsorption capability and is particularly suitable for use in hygiene articles.